SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26ae4270293936dc695315db18b317b1e3e527d66166d35de222f6578fad3699' 
  AND token = 'fpWwjm8XNAIPGH63cc1HxEvp+FTSagD348SXTmxCa4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}